Device and method for limiting or keeping constant a flowing quantity of liquid

ABSTRACT

A device for limiting or keeping constant a quantity of fluid flowing therethrough, includes: a housing with a front chamber and a rear chamber; a partition arranged in the housing with two or more openings; and a flow limiting element arranged in one or both openings. The flow limiting element includes a housing provided with an inlet, an outlet and a throughflow opening; and a resilient plate-like valve element mounted in the housing, substantially able to close the throughflow opening by resilient movement in the direction of a valve seat arranged in the housing adjacently of the throughflow opening. The valve element is fixed on one side and can move resiliently on the opposite side in the direction of the valve seat. A mould produces one or more injection-moulded products. The injection-moulded product is a flow limiter for limiting the force of the flow of a fluid flowing therethrough.

The present invention relates to a device for limiting and/or keepingconstant a quantity of liquid flowing therethrough.

The invention also relates to a method for producing one or moreinjection-moulded products, and a mould.

Clean drinking water is a scarce resource in many regions of the world.In the Western world a great deal of water is wasted by individuals intaking a bath or shower. Despite the fact that many measures have beentaken in Western countries, the amount of energy involved in a shower orbath has continued to increase relatively.

Pressure-independent flow limiters are marketed very successfully byapplicant, particularly in the United Kingdom and other countries. Suchflow limiters are described in EP 1.131.687 A and the Netherlands patentapplication no. 1010592.

Compared to flow limiters of other manufacturers, which usually make useof rubber brings and the like, a considerable improvement is obtainedwith these known flow limiters, this being due to the ability of theseknown flow limiters of applicant to provide over a period of years anaccurate flow rate of for instance 7.8 (+/−0.1) litres per minute withina (dynamic) pressure interval of 2.5-10 bar. Existing flow limiters ofother manufacturers appear in practice to generate a much less constantand accurate flow rate, particularly in the case of pressure loss(pressure drop), this being particularly undesirable in the case ofshowers and the like and with the aim of comfortable use of water.

There is also a need in hotels, cruise ships and in (the petrochemical)industry for flow limiters in order to limit and/or keep constant theforce of a flow of liquid. Owing to the flow limiters of applicant waterutility companies can determine more precisely the capacity of therequired installations when such flow limiters are arranged in hotels,office buildings, private residences and the like at many locations inthe area which they supply. Savings in the costs of installations arehereby considerable.

An essential element of the flow limiter of applicant is manufactured bymeans of injection moulding. It is important for the operation of manyinjection-moulded products that the dimensioning of these manufacturedproducts corresponds to the required specifications. Particularly in thecase of flow limiters which aim to be pressure-independent, thedimensioning of different components is found to be critical inobtaining effective operation.

A first object of the present invention is to further improve and makeknown flow limiters available over a wide range of flow rates.

A second object of the present invention is to manufactureinjection-moulded products in large numbers with a very high precision,in particular flow limiters with an accurate flow rate.

According to a first aspect, the present invention provides for thispurpose a device for limiting a quantity of fluid flowing therethrough,comprising a housing which comprises a front chamber and a rear chamber;a partition arranged in the housing and provided with two or moreopenings; and a flow limiting element arranged in one or both openings.

It becomes possible with this device to determine more precisely thepeak load of the water use in for instance a large city or industrialzone, the more so in that the device can be arranged at many locationsin a mains system. A very large amount of money can be saved bydetermining this peak load, as disproportionately high costs areinvolved in managing and supply of peak requirements.

In further preferred embodiments of the invention the partition isdisc-shaped and provided with two, three, four, five and preferably sixor seven openings. Many more openings can also be envisaged in otherapplications, for instance 10-20, 20-30, 30-40, 40-50 and so on.Arranged in a least one of these openings is a flow limiting elementwhich preferably comprises a resilient part for the purpose of limitingthe flow rate when pressure increases, wherein the resilient part ispreferably embodied in plastic or metal.

The housing is preferably constructed from four parts with sealing ringstherebetween so that it is easy to disassemble using screw bolts and oneor more openings for a flow limiter can be sealed with a (releasable)plug or blind plate and subsequently reassembled. The flow rate can beadapted as desired by providing or sealing one or more openings of aflow limiting element. It is thus possible to utilize the device in manyfields of application.

In a further preferred embodiment the flow limiting element comprises ahousing provided with an inlet, an outlet and a throughflow opening; anda resilient plate-like valve element which is mounted in the housing andwhich can substantially close the throughflow opening by resilientmovement in the direction of a valve seat arranged in the housingadjacently of the throughflow opening, wherein the valve element isfixed on one side (by the liquid flow) and the valve element (resilientelement) can move resiliently on the opposite side in the direction ofthe valve seat, wherein at least a part of the surface of the valve seatextends on the side remote from the fixed side of the valve element suchthat the distance between the valve seat and the valve element isgreater at the position of the outer peripheral edge of the valve seatthan at the position of the inner peripheral edge of the valve seat.

Said part of the surface of the valve seat preferably extends obliquely.

Because said part of the surface of the valve seat extends in this way,a pressure with an upstream component is realized on the downstream sideof the valve element so that the valve element does not close thethroughflow opening even at very high pressure and, in the case of asudden pressure decrease at the inlet of the housing, instantaneouslyenlarges the throughflow opening in order to maintain the most constantpossible flow rate at the outlet.

According to a further preferred embodiment, the distance between theouter and inner diameter of said part of the valve seat amounts to 5% to40%, preferably 10% to 20% of the distance between the fixed side of theresilient part of the valve element and the resiliently movable outerend of the valve element.

This ratio determines the above stated upstream counter-pressure on thedownstream side of the valve element and is therefore crucial to acorrect operation of the flow limiting element.

In a further preferred embodiment the surface of the valve seat iscurved such that the distance between the valve seat and the freelymoving part of the valve element is greater at the end of theresiliently movable part of the valve element than at the fixationpoint.

In a further preferred embodiment the valve seat comprises cam parts forlimiting the stroke of at least a part of the freely moving part of thevalve element.

These cam parts ensure that the valve element sags progressivelyrelative to the longitudinal axis of the resilient part of the valveelement, whereby the flow rate at the outlet of the housing is keptconstant in even more accurate manner. It is thus possible for the valveelement to operate optimally at both low and high pressures.

In a further preferred embodiment the valve seat has between said partof the valve seat and the fixation point of the valve element at leastone recess which locally increases the distance between the valveelement and the valve seat.

This recess provides for a swirling flow on the downstream side of thevalve element and has the advantage that the direction of the liquidflow at the outlet is substantially the same as the direction of theliquid flow at the inlet, wherein a good throughflow is moreoverprovided.

In further preferred embodiments the valve element is of sheet steeland/or mounted releasably in the housing and/or supported on a supportpoint in the housing by means of an eccentric hole in the valve element.

More preferably applied is spring steel, i.e. hardened sheet steel.

According to a further preferred embodiment, the housing comprises acushion part which, together with the support point, determines thedegree of clamping of the valve element at the end of the fixed part ofthe valve element. The degree to which the valve element opens canhereby be determined.

The invention also relates to a flow limiting element for limiting theforce of the flow of a fluid flowing therethrough, comprising: a housingprovided with an inlet, an outlet and a throughflow opening; and aresilient plate-like valve element which is arranged in the housing andwhich can substantially close the throughflow opening by resilientmovement in the direction of a valve seat arranged adjacency of thethroughflow opening in the housing, wherein the valve element is fixedon one side and the valve element can move resiliently on the oppositeside in the direction of the valve seat, wherein at least a part of thesurface of the valve seat extends on the side remote from the fixed sideof the valve element such that the distance between the valve seat andthe valve element is greater at the position of the outer peripheraledge of the valve seat than at the position of the inner peripheral edgeof the valve seat.

Because said part of the surface of the valve seat extends in this way,the valve element does not close the throughflow opening even at veryhigh pressure and, in the case of a sudden pressure decrease at theinlet of the housing, instantaneously enlarges the throughflow openingin order to maintain the most constant possible flow rate at the outlet.

The invention also relates to a method for limiting or keeping constanta quantity of flowing fluid, wherein the fluid is mixed in a frontchamber in a housing, flows through openings in a partition arranged inthe housing and provided with flow limiters and/or plugs and comestogether again in a rear chamber arranged behind the partition in thehousing, wherein the flow rate of the fluid is limited in at least oneopening.

According to a preferred embodiment of the method, the flow rate isdependent on one or more openings with flow limiting elements and one ormore openings which are covered.

The flow rate can be adapted as desired by providing one or moreopenings with a flow limiting element or by covering one or moreopenings. It is thus possible to utilize the device in many fields ofapplication.

The invention also relates to a method for spraying clean facades,walls, ships, aircraft, cars, trucks and the like wherein the flow rateis determined by the flow rate of one flow limiting element multipliedby the number of openings in which the flow limiting elements arearranged.

According to a second aspect, the invention provides a mould forproducing one or more injection-moulded products, wherein at least apart of the mould is movable and adjustable such that the size and/orthe shape of the mould cavity is adjustable.

According to a preferred embodiment, the one or more movable parts ofthe mould are adjustable from the outer side of the mould.

The mould need hereby neither cool nor be opened in order to change theshape of the mould cavity. Because the mould cavity can be changedduring the injection moulding process, the dimensioning or design of theproduct can be efficiently modified as desired without appreciableinterruptions in the injection moulding process.

An injection moulding process must in this context preferably beunderstood to mean the manufacture of a series of products by injectionmoulding. The modification or changing of the mould for the purpose ofmodifying the product to be manufactured then preferably takes placebetween two successive production cycles, wherein a cycle can beunderstood to mean either the manufacture of one product or a pluralityof products simultaneously. It is then particularly advantageous thatthe mould can be changed without the mould having to cool and/or bedisassembled.

According to a further preferred embodiment, the injection-mouldedproduct is a flow limiting element for limiting the force of the flow ofa fluid flowing therethrough, comprising: a housing provided with aninlet, an outlet and a throughflow opening; and a resilient plate-likevalve element which is mounted in the housing and which cansubstantially close the throughflow opening by resilient movement in thedirection of a valve seat arranged adjacency of the throughflow openingin the housing, wherein the valve element is fixed on one side and thevalve element can move resiliently on the opposite side in the directionof the valve seat.

The dimensioning of the different components is particularly importantin the case of flow limiting elements which aim to bepressure-independent. The precision of the dimensioning of thesecomponents determines the accuracy with which a constant flow rate canbe maintained at the outlet.

According to further preferred embodiments, the movable part isadjustable for the purpose of adapting the dimensions, the shape and/orthe location of the valve seat which determines the width and length ofa gap between the valve element and the valve seat; protruding camelements on the valve seat which limit the stroke of at least a part ofthe freely moving part of the valve element; the location of the camparts relative to the valve seat; and the mounting means for the valveelement (or resilient element).

Because the dimensions, the shape and/or the location of the valve seat,the cam parts and the mounting means can be adapted, optionally relativeto each other, the stroke, the degree of clamping and the supporting ofthe valve element and the gap dimensions can be influenced, and anaccurate constant flow rate can be realized at the outlet of the flowlimiting element at both relatively high and relatively low pressure. Itis particularly advantageous for the cam parts to be situated on thevalve seat and for the height of the cam parts to be adjustable relativeto the valve seat. This ensures that the gap dimensions, determined bythe stroke of the valve element on the one hand and the height and/orwidth of the valve seat on the other, can be optimized.

According to a preferred embodiment, the movable part is adjustable bymeans of adjusting screws and/or adjusting means which taper and pushagainst the movable part such as to provide for a continuously variableadjustment of the movable part.

The movable part can hereby be adjusted with great precision in order toobtain an extremely precise dimensioning of the injection-mouldedproduct.

In a further preferred embodiment a resilient element is provided forthe purpose of pushing the movable part outward relative to the mouldcavity during the movement of the adjusting screw and/or the adjustingmeans to the outer side of the adjustable mould.

This resilient element also contributes in particular toward a preciseadjustment in a controlled manner of the movable mould cavityshape-defining part.

The invention further relates to a method for producing one or moreinjection-moulded products, wherein the injection-moulded product ismanufactured in a mould according to any of the claims 1-10, whereinbetween the manufacture of two injection-moulded products at least apart of the mould is moved such that the size and/or shape of the mouldis adjusted.

According to a preferred embodiment, the movable part of the mould isadjusted from the outer side of the mould.

According to a further preferred embodiment, at least a part of themould is moved such that the size and/or the shape of the mould isadjusted without disassembling the mould.

The mould need hereby neither cool nor be disassembled in order tochange the shape of the mould cavity. Because the mould cavity can bechanged during the injection moulding process, the dimensioning ordesign of the product can be modified efficiently as desired withoutappreciable interruptions in the injection moulding process.

According to yet another preferred embodiment, the movable part isadjusted subject to a variation in thickness and/or composition of thevalve element.

This is particularly advantageous so as to be able to correct for avariation in thickness and/or precise composition of the material of theresilient valve element between manufacture of different series of valveelements. Even within one roll of spring steel the properties of thesheet steel can already vary such that adjustment of the mould isdesirable, e.g. after a considerable part of the roll has been unrolled.The dimensioning of the different components of the injection-mouldedproduct can be modified subject to for instance tests between productioncycles.

Further advantages, features and details of a first and second aspect ofthe present invention are elucidated on the basis of the followingdescription of preferred embodiments thereof with reference to theaccompanying drawings, in which:

FIG. 1 is a partially cut-away perspective view of a preferredembodiment of a device according to the present invention;

FIG. 2 shows the perspective view of the device of FIG. 1 with a greaterflow rate;

FIG. 3 is an exploded view of the device according to FIGS. 1 and 2:

FIG. 4 is a view in partial cross-section along the line IV-IV in FIG.2;

FIG. 5 is a view in partial cross-section along the line V-V in FIG. 1;

FIG. 6 is a partially cut-away view of another preferred embodiment;

FIG. 7 shows a longitudinal section through the embodiment of FIG. 6;and

FIG. 8 shows a cross-section through the embodiment of FIG. 6;

FIG. 9 shows a cross-section through a preferred embodiment of the flowlimiting element under an inlet pressure less than or equal to 3 bar;

FIG. 10 is an enlarged view of a part of the cross-section of the flowlimiting element as shown in FIG. 9;

FIG. 11 shows a cross-section of the flow limiting element under aninlet pressure of 4 bar;

FIG. 12 is an enlarged view of a part of the cross-section of the flowlimiting element as shown in FIG. 11;

FIG. 13 shows a cross-section of the flow limiting element under aninlet pressure of 5 bar;

FIG. 14 is an enlarged view of a part of the cross-section of the flowlimiting element as shown in FIG. 13:

FIG. 15 is a top view of the housing of the flow limiting element;

FIG. 16 is a side view of the housing of the flow limiting element;

FIG. 17 is a perspective view of a preferred embodiment of theadjustable mould;

FIG. 18 is a side view of the adjustable mould;

FIG. 19 shows an overview of the movable parts of the mould;

FIG. 20 shows the movable component of the mould with which the heightof a cushion part of the housing of the flow limiting element can bedefined;

FIG. 21 is a side view of the movable component of the mould with whichthe height of a cushion part of the housing of the flow limiting elementcan be defined;

FIG. 22 shows the movable component of the mould with which the heightof a valve seat of the flow limiting element can be defined:

FIG. 23 shows the movable component of the mould with which the heightof cam parts of the housing of the flow limiting element can be defined;

FIG. 24 shows the movable component of the mould with which the heightof a support part of the housing of the flow limiting element can bedefined.

A preferred embodiment of a device 10 (FIG. 1) according to the presentinvention comprises a housing 11 in which is received a centralpartition 12 with six openings 13, 14, 15, 16, 17 and 18, of whichthree, 14, 16 and 18, are covered with cover plates 19. An inlet tube 21and an outlet tube 22 are connected to the housing. Inlet tube 21debouches in a front chamber 23 which is shown in broken lines and issituated opposite outlet tube 22 in rear chamber 24. In FIG. 2 the coverplates 19 are removed so that device 10 according to FIG. 2 allows sixtimes the quantity of liquid to pass through within a determinedpressure range of for instance 6×5.0 litres per minute or 6×7.8 litresper minute, this is in contrast to the embodiment shown in FIG. 1 whereonly three times this flow rate can flow through.

It will be apparent that the preferred embodiment according to thepresent invention has a wide variation in possible flow rates, i.e. from1×5.0 litres to 6×7.8 litres and all flow rates between, for instance2×5.0 litres and 3×7.8 litres.

Flow limiting elements 31 (FIG. 3) are easily exchangeable from adisc-shape central part 32. The foremost part 23 of the housing enclosesa gasket 37 which on the one hand is tightened fixedly against and sealson disc 35 using screw bolts 33, while further seals 36 and 37 realizethe scaling between respectively disc 35 and central part 32 and rearpart 24 and disc 32.

In FIG. 4 screw bolts 33 protrude from rear housing part 24 throughholes in central part 32 and are screwed fixedly into front housing part23, wherein disc 35 holds throughflow elements 31 in their place.

Cover plates 19 (FIG. 5) cover the flow limiting elements 31 whichcomprise a resilient part with limited stroke as well as distributor 51and an outlet part 52.

A liquid can flow through such an element 31 at an extremely constantflow rate within a dynamic pressure range of 2.5-10 bar.

As will be apparent from the above, a preferred embodiment of the deviceaccording to the present invention can be made suitable for manyapplications, wherein six (or more or fewer) flow limiting elements withdiffering flow rates, for instance 5 litres per minute or 7.8 litres perminute, can be applied in varied manner. Because of the chambers on theinflow and outflow side the liquid flows are properly mixed while theproduct is easy to disassemble and can be reassembled for an applicationwherein a higher or lower flow rate is desired. A user can exchange thedifferent flow limiting elements in simple manner and optionally providethem with a cover plate. A relatively large front chamber offers littleresistance, can easily mix hot and cold liquid and causes substantiallyno unnecessary sound or noise.

The front and rear chambers can be made wholly dome-shaped, which in alllikelihood provides an even better operation than the truncated coneshape as shown and described.

In a further embodiment (FIGS. 6, 7 and 8) two dome-shaped housing parts61, 62 are screwed fixedly to each other. Following unscrewing apartition-like component is left clear so that one or more of thelimiting elements can be exchanged.

FIG. 9 shows a cross-section of a preferred embodiment of the flowlimiting element consisting of a cylindrical housing 101 provided withan inlet 102 and an outlet 103 for a liquid flow and a plate-likeresilient valve element 104 for limiting the liquid flow. The plate-likeresilient valve element 104 is supported on a support part 105 in thecentral downstream part of housing 101, wherein said support part 105and a cushion part 106 in the peripheral upstream part of housing 101hold in place a fixed part 107 of valve element 104. This fixation isbrought about as follows. The resilient valve element 104 in principlelies unattached in housing 101 and is supported on one side over thewhole width by support part 105 and held in place by a pin on supportpart 105 which fits loosely in a hole arranged in resilient element 104.Both sides, the smaller fixed part 107 and the larger resilient part 108of the resilient element are exposed to the water pressure and a forceis therefore exerted on both sides. The outer end of part 107 on theopposite side of resilient element 104 rests against cushion 106,whereby the valve element is fixed in its position by the flow of theliquid. The size of the throughflow opening can be adjusted in the reststate of valve element 104 by adjusting the thickness of cushion 106.The resilient part 108 of valve element 104 determines, together with avalve seat 109 with thickness 110 inclining downward to the outer end ofresilient part 108, the width and length of a narrowing gap 111, whereinsaid gap 111, together with the space 112 lying on the liquid outletside of resilient element 104, realizes a pressure drop such that theliquid flow rate at the outlet is constant. In housing 101 protrudingparts 113 and 114 are also arranged on valve seat 109 such that underthe influence of the inlet pressure they limit the stroke of resilientelement 104. Each pair of cams 113, 114 is arranged asymmetrically, i.e.the distance of the two cams 113, 114 from the fixation point differs tosome extent. This creates bias in the resilient valve element 104,whereby vibrations of valve element 104 are prevented. Also arranged invalve seat 109 are recesses 115 which influence the liquid flow in theflow limiting element such that the direction of the outgoing liquidflow is substantially the same as the direction of the ingoing liquidflow. A filter 116 is also situated at inlet 102 and a distributor 117at outlet 103.

FIG. 10 shows an enlarged view of a part of FIG. 9, wherein the positionof resilient element 104 is shown under an inlet pressure of 3 bar. FIG.10 also shows an enlarged view of support part 105 and cushion part 106,valve seat 109 with thickness 110, gap 111, cam parts 113 and 114 andrecesses 115.

FIGS. 11 and 13 show cross-sections of the preferred embodiment of theflow limiting element as described in the description of FIG. 9 under aninlet pressure of respectively 4 and 5 bar.

FIGS. 12 and 14 show enlarged views of respectively FIGS. 11 and 13,wherein the stroke of resilient element 104 limited by cam parts 113 and114 is shown at an inlet pressure of respectively 4 and 5 bar. Shown isthat at an inlet pressure of 4 bar the flexible part 108 of resilientelement 104 rests on cam part 113 and that at an inlet pressure of 5 barthe flexible part 108 of resilient element 104 rests on cam parts 113and 114.

FIG. 15 is a top view of housing 101 of a preferred embodiment of theflow limiting element which shows support part 105, valve seat 109 withthickness 110, cam parts 113 and 114 arranged on valve seat 109 andrecesses 115 arranged in valve seat 109.

FIG. 16 is a side view of housing 101 of a preferred embodiment of theflow limiting element which, in addition to the parts stated in FIG. 15,shows cushion part 106 and the inclination of valve seat 109.

FIG. 17 is a perspective view of a preferred embodiment of an adjustablemould 118 according to the present invention, wherein mould 118 isconstructed from a plurality of composite and separate (steel)components. The mould can be divided into a front mould 150 and rearmould 160. Mounted on both the front mould 150 and rear mould 160 aretensioning plates, here the shown front plate 133 and rear plate 134which hold together the (intermediate) components of mould 118. Acentering ring 135 and a sprue bush 136 are arranged in front plate 133.Front mould 150 consists of an injection nozzle 151 and a shaping plate152 which comprises a cavity which defines the dimensions and shape ofthe injection-moulded product. Rear mould 160 consists of a shapingplate 161, an adjusting plate 162 for adjusting the movable componentsof the mould, a support plate 163 and an ejector mechanism. The ejectormechanism comprises an ejector 137, an ejection plate 138, an ejectioncover plate 139 and ejector pins for releasing the injection-mouldedproducts from mould 118 following cooling of mould 118, which pins mustengage on the greatest possible surface area of the product in order toprevent denting in the injection-moulded product. The shape of the mouldcavity also determines how smoothly the injection-moulded product can beejected. Cooling channels for cooling are situated around the cavity. Acorrect position of these channels is crucial in preventing theoccurrence of temperature differences which can result in deformation ofthe injection-moulded product.

In known moulds so-called inserts, i.e. metal plates of differing form,are necessary to enable shaping of the product, for instance when theproduct has a specific protrusion. When the two halves of the mould moveapart, the inserts can be displaced with different pin constructions sothat the shape of the product can be changed. The adjustable mould 118has the great advantage that these inserts are adjustable from outsidewhen the mould is still warm. As a result the mould does not need tofirst cool or be disassembled in order to modify the shape anddimensioning of the injection-moulded product between the manufacture oftwo products. Mould 118 is typically manufactured from steel oraluminium, also because of the heat-exchanging property required forcooling purposes.

FIG. 17 also shows adjusting screws 119 to 122 which can be turned viaopenings in cover plates 142 and 143 for adjusting movable parts inmould 118 for the purpose of modifying the dimensions and shape of theinjection-moulded product, wherein by means of the front view of theadjustable mould 118 shown in FIG. 18 is shown that mould 118 comprisesa so-called multiple mould and is suitable for producing a plurality ofinjection-moulded products simultaneously—in the shown preferredembodiment four products 128 to 131—wherein the dimensions ofinjection-moulded products 128 to 131 can be changed independently ofeach other and during the injection moulding process by means of theadjusting screws 119 to 122.

FIG. 19 is a perspective view of mould components 132 of a preferredembodiment of mould 118 which defines the counter-mould for one of theplurality of injection-moulded products 128 to 131, wherein thedimensions of the above stated support part 105, valve seat 109 and camparts 113 and 114 can be changed by adjusting parts movable in the mouldby means of the respective adjusting screws 119, 121 and 122 which arelocated in adjusting plate 162 and can be operated through openings incover plate 142, and cushion part 106 by means of adjusting screw 120which is situated in front plate 133 and can be operated through anopening in cover plate 143. FIG. 19 also shows one of the four ejectorpins 127 for releasing one of the plurality of stated injection-mouldedproducts 128 to 131 from mould 118 following cooling of mould 118.

FIG. 20 is a perspective view of mould components 132 of a preferredembodiment of mould 118 which define the counter-mould for one of theplurality of injection-moulded products 128 to 131, wherein theadjustable mould component 123 is shown for changing the dimensions ofcushion part 106 along the longitudinal axis of the mould by means ofturning the adjusting screw 120 situated in front plate 133. Across-section of this adjusting screw 120 and the movable cavityshape-defining mould component 123 with recess 106′ is shown togetherwith a cross-section of housing 101 of the flow limiting element in FIG.21 by way of illustrating the operation of recess 106′ in this movablecomponent 123 on cushion part 106 of housing 101. The cross-section ofFIG. 21 also shows the operation of the adjusting screw on the cavityshape-defining component 123, and clarifies how the adjusting means oradjusting screw 120 moves and tapers due to adjustment, this providingfor a continuously variable adjustment of component 123. FIG. 21 alsoshows a resilient element 141 for moving component 123 outward relativeto the cavity when the adjusting screw is turned toward the outer sideof adjustable mould 118.

FIG. 22 to 24 are perspective views of mould components 132 of apreferred embodiment of mould 118 which define the counter-mould for oneof the plurality of injection-moulded products 128 to 131, wherein therespective mould components 124, 125 and 126 adjustable along thelongitudinal axis of the mould are shown for changing the dimensions,shape and/or sizes of respectively the valve seat 109, cam parts 113 and114 and support part 105 by means of turning respective adjusting screwsor adjusting means 121, 122 and 119. These are also adjusting meanswhich move in a channel which tapers due to the shape and the positionof the movable component determined by the resilient elements (such asresilient element 141 as shown in FIG. 21), this providing for acontinuously variable adjustment of the cavity shape-definingcomponents.

The present invention is not limited to the above described preferredembodiment; the rights are defined by the claims, within the scope ofwhich many modifications can be envisaged.

1.-19. (canceled)
 20. Flow limiting element for limiting the flow of afluid flowing therethrough, comprising: a housing provided with aninlet, an outlet and a throughflow opening; and a resilient plate-likevalve element, mounted in the housing, substantially able to close thethroughflow opening by resilient movement in the direction of a valveseat arranged adjacency of the throughflow opening in the housing,wherein the valve element is fixed on one side and the valve element isresiliently movable on the opposite side in the direction of the valveseat, wherein at least a part of the surface of the valve seat extendson the side remote from the fixed side of the valve element such thatthe distance between the valve seat and the valve element is greater atthe position of the outer peripheral edge of the valve seat than at theposition of the inner peripheral edge of the valve seat. 21-23.(canceled)
 24. Mould for producing one or more injection-mouldedproducts, the mould comprising: an outer housing forming a mould cavitytherein; and a counter-mould disposed in the mould cavity; wherein atleast a part of the counter mould is movable and adjustable such that atleast one dimension of the counter mould is adjustable and at least oneof a size and shape of the mould cavity is adjustable, wherein themovable part of the counter mould is adjustable from an outer side ofthe mould, wherein at least a part of the counter mould is adjustablymovable such that the at least one of the size and the shape of themould cavity is adjusted without disassembling the mould, wherein themovable part is adjusted subject to a variation in at least one ofthickness and composition of a valve element of the injection-mouldedproduct, wherein a portion of mould is configured to form a flowlimiter, as the injection-moulded product, for limiting flow of a fluidflowing therethrough, a housing of the injection moulded productprovided with an inlet, an outlet and a throughflow opening; and aresilient plate-like valve element of the flow limiter, mounted in thehousing, substantially able to close the throughflow opening byresilient movement in a direction of a valve seat arranged adjacency ofthe throughflow opening in the housing, wherein the valve element isfixed on one side and the valve element is resiliently movable on theopposite side in the direction of the valve seat. 25-33. (canceled) 34.Method for producing one or more injection-moulded products, wherein theinjection-moulded product is manufactured in a mould for producing oneor more injection-moulded products, wherein at least a part of acounter-mould within a cavity of the mould is movable and adjustablesuch that at least one of a size and shape of a mould cavity isadjustable the method comprising: moving, between the manufacture of twoinjection-moulded products, at least a part of the mould such that adimension of the counter-mould and at least one of a size and shape ofthe mould cavity is adjusted, wherein the movable part of the countermould is adjusted from an outer side of the mould, wherein the movablepart is adjusted subject to a variation in at least one of thickness andcomposition of a valve element; producing a flow limiter, as theinjection-moulded product, for limiting flow of a fluid flowingtherethrough; producing a housing provided with an inlet, an outlet anda throughflow opening; and producing a resilient plate-like valveelement, mounted in the housing, substantially able to close thethroughflow opening by resilient movement in a direction of a valve seatarranged adjacency of the throughflow opening in the housing, whereinthe valve element is fixed on one side and the valve element isresiliently movable on the opposite side in the direction of the valveseat. 35-37. (canceled)